Response of Brachiaria brizantha cv. Xaraés to liming

Abstract

The response of Brachiaria brizantha var. Xaraés to the application of dolomitic lime (0; 800; 1,600; 2,400 and 3,200 kg/ha; PRNT = 100%), broadcasted and incorporated into the soil 2 months before planting, was evaluated under greenhouse with natural conditions of light and temperature. The soil was a Yellow Latosol, with clayey texture (pH = 5.5; Al = 1.5 cmolC/dm3; Ca + Mg = 1.7 cmolC/dm3; P = 2.0 mg/kg; and K = 59 mg/kg). A randomized block design was used with three replications. At establishment, a uniform application was made of 40 mg/dm3 of nitrogen (urea), 22 mg/dm3 of P2O5 (triple superphosphate), and 40 mg/dm3 of K2O (potassium chloride). The application of lime increased dry matter (DM) production significantly as well as the nitrogen, phosphorus, calcium, and magnesium concentrations in the plant. Maximum DM yield and phosphorus, calcium, and magnesium contents were obtained with the application of 3,087; 2,300; 3,123 and 3,111 kg lime/ha, respectively. Critical internal levels of calcium and magnesium related to 80% maximum DM production were estimated in 4.17 and 3.35 g/kg, respectively.